Brake



'Sept. 26, 1933. w. H. DELAHAYE v 1,928,050

BRAKE Filed Dec. 2, 1929 mvzwrosz: WALTER H DELAHAYE.

Patented Sept. 26, 1933 UNITED STATES PATENT OFFICE assignor to Bendix Brake Company,

Bend, Ind.

Application December 2,

13 Claims.

The object of this invention is to provide a brake operated by either a cam, toggle or the like with a servo shoe of simple construction so coupled to the applying means that the servo force set up is applied through the minimum number of parts, thus simplifying the construction and providing one that is not liable to become deranged, so that the whole brake is such that it will retain its efficiency with the least possible attention. These objects arev accomplished by the use of a servo shoe sliding on one of the main shoes similar to that set forth in, for example, applicants copending Appln. Serial No. 410,941, filed December 2, 1929 and the specific details of which it is therefore not necessary to set forth herein.

The invention consists in the construction, combination and arrangement of parts hereinafter described and more particularly pointed out in the appended claims.

The drawing hereunto appended illustrates, by way of example, two embodiments of the improved structure,

Figure 1 being an elevation of the invention applied to a cam-operated brake, and

Figure 2 an elevation of the invention applied to a brake employing the well known type of toggle. Referring to the drawing in which similar parts are designated by the same numerals in both figures, 1 represents the usual brake drum in which a pair of shoes 2 and 3 are pivoted on the anchor 4. In the cam brake (Figure 1) these shoes have the customary cam engaging surfaces 5 and 6, adapted to be engaged by the cam 7, which is operated by "the usual lever 8 adapted to be connected to the brake rigging. The shoe 2 is of the usual type and has no additional features but the shoe 3 carries a servo shoe 9 as fully set forth in the above mentioned co-pending application. Briefly, this shoe is adapted to slide on an offset portion 10 of the shoe 3, which acts as a guide for the servo shoe instead of being furnished with a friction surface. Unlike the servo shoes disclosed in other application, in the construction herein disclosed, the servo shoe 9 which operates on the guide 10 has an arcuate extension 11 which is provided with gear teeth which engage with the teeth of a segmental gear 12 fast on the shaft of the cam '7 or integral therewith.

Referring to Figure 2, it will be seen that the servo may be similarly directly connected by interengaging teeth to the toggle applying means. This toggle applying means consists of the toggle 13 operated by the lever 14 through the arm 15 which is connected to the toggle 13 by means of the link 16. The toothed extension 11 in this South 1929. Serial No. 410,938 (01. 188-78) case is made to mesh with the section of a gear that is fast to the pivot pin securing the toggle to the shoe 3, or which may be directly out in the extremity of the arm of the toggle, the latter construction being shown in the drawing.

Various modifications may be made in the device and it is the intention of the applicant to claim all variations of construction in the scope of the appended claims.

I claim:

1. In a brake and in combination with a fixed support, a pair of shoes thereon, driver-operated applying means for the shoes and aservo shoe slidable on one of the shoes, said servo shoe and said applying means having inter-engaging parts adapted to transmit the servo action of the former to the latter means.

2. In a brake and in combination with a fixed support, a pair of shoes on said support, driveroperated means for expanding the free end of said shoes, and a servo shoe carried by one of the shoes, said servo shoe and said expanding means having inter-engaging parts to transmit the servo action of the servo shoe to the expanding means.

3. In a brake and in combination with a fixed support, a pair of shoes thereon, expanding driver-operated means between the free ends of said shoes, said expanding means including a toothed member, and a servo shoe carried by one of the shoes, said servo shoe having a toothed extension engaging the first mentioned toothed part to transmit a servo action from the servo shoe to the applying means.

4. In a brake and in combination with a fixed support, a pair of shoes thereon, expanding driver-operated means between the free ends of the said shoes, said expanding means including a pivoted part having a toothed section, and a servo shoe sliding on one of the first mentioned shoes near the free end thereof, an extension on the servo shoe having an arcuate toothed section adapted to engage the first mentioned toothed section to transmit a servo action from the servo shoe to the said expanding means.

5. In a brake and in combination with a fixed support, a pair of shoes on said support, a pair of shoes pivoted on said support, a cam for expanding the shoes situated between the free ends of said shoes, a shaft for operating the said cam, means to operate the shaft, a servo shoe mounted to slide on one of the shoes near the free nd thereof, and inter-engaging means on the servo shoe and the shaft to transmit the servo action of the servo shoe to the shaft and the cam carried thereby.

6. In a brake and in combination with a fixed support therefor, shoes movable thereon, expanding driver-operated means between two adjacent ends of the shoes, a servo shoe sliding on one of said ends, and inter-engaging portions on the expanding means and the servo shoe to transmit a servo action from theservo shoe to the expanding means.

7. In a brake and in combination with a. fixed support therefor, a set of shoes mounted on said support adapted to be expanded into contact with a co-operating brake drum, means for causing the said expansion, a servo shoe carried adjacent the extremity of one of the shoes and sliding thereon adjacent the expanding means, a rotating part of the expanding means having a toothed portion and the said servo shoe having an extension overlying said toothed portion and having complementary teeth adapted to mesh therewith to transmit a servo action from the servo shoe to the expanding means.

8. In a brake and in combination with a fixed support therefor, a set of shoes mounted thereon, one of said shoes having an inwardly offset portion on which is slidably mounted a servo shoe adjacent an end thereof, expanding means for the said set of shoes between said end carrying the servo shoe and the next adjacent shoe, said expanding means including a shaft having a toothed portion carried thereby, an arcuate toothed extension on the said sliding servo shoe guide on the friction element, a servo shoe slid-s able on the guide, an extension on the servo shoe and gear teeth on the extension.

11. A brake comprising friction elements having separable ends, a servo shoe movable on one of the ends and means for spreading the separable ends including a gear segment for actuating the servo shoe.

12. A brake comprising friction elements having separable ends, a servo shoe movable on one of the separable ends, a rack on the servo shoe, a cam for spreading the separable ends and a gear segment associated with the cam and movable concomitantly therewith to actuate the servo shoe.

13. A brake comprising friction elements having separable ends, a servo shoe movable on one of the ends, a rack on the servo shoe, a toggle for spreading the separable endsof the friction element and a gear segment on the toggle engaging the rack on the servo shoe and means for applying force to the toggle.

WALTER I-I. DELAHAYE. 

